// 背景图片
bg-image($url)
  background-size cover
  background-repeat no-repeat
  background-image url($url + "@2x.png")
  @media (-webkit-min-device-pixel-ratio: 3),(min-device-pixel-ratio: 3)
    background-image url($url + "@3x.png")

// 单行省略号
no-wrap()
  text-overflow ellipsis
  overflow hidden
  white-space nowrap

// 多行省略号
no-wrap-n(n)
  overflow hidden
  text-overflow ellipsis
  white-space normal
  display -webkit-box
  -webkit-line-clamp n
  -webkit-box-orient vertical

// 扩展点击区域
extend-click()
  position: relative
  &:before
    content: ''
    position: absolute
    top: -10px
    left: -10px
    right: -10px
    bottom: -10px

// Clearfix
//
// For modern browsers
// 1. The space content is one way to avoid an Opera bug when the
//    contenteditable attribute is included anywhere else in the document.
//    Otherwise it causes space to appear at the top and bottom of elements
//    that are clearfixed.
// 2. The use of `table` rather than `block` is only necessary if using
//    `:before` to contain the top-margins of child elements.
//
// Source: http://nicolasgallagher.com/micro-clearfix-hack/
clearfix()
  &:before,
  &:after
    content " " // 1
    display table // 2
  &:after
    clear both
